Dual neutralization of TNFR-2 and MMP-2 regulates the severity of S. aureus induced septic arthritis correlating alteration in the level of interferon gamma and interleukin-10 in terms of TNFR2 blocking. Immunol Res. 2018;66:97-119. [PMID: 29218573 DOI: 10.1007/s12026-017-8979-y]

Eicosanoid profiles in an arthritis model: Effects of a soluble epoxide hydrolase inhibitor

Rheumatoid arthritis is a common systemic inflammatory autoimmune disease characterized by damage to joints, inflammation and pain. It is driven by an increase of inflammatory cytokines and lipids mediators such as prostaglandins. Epoxides of polyunsaturated fatty acids (PUFAs) are lipid chemical mediators in a group of regulatory compounds termed eicosanoids. These epoxy fatty acids (EpFA) have resolutive functions but are rapidly metabolized by the soluble epoxide hydrolase enzyme (sEH) into the corresponding diols. The pharmacological inhibition of sEH stabilizes EpFA from hydrolysis, improving their half-lives and biological effects. These anti-inflammatory EpFA, are analgesic in neuropathic and inflammatory pain conditions. Nonetheless, inhibition of sEH on arthritis and the resulting effects on eicosanoids profiles are little explored despite the physiological importance. In this study, we investigated the effect of sEH inhibition on collagen-induced arthritis (CIA) and its impact on the plasma eicosanoid profile. We measured the eicosanoid metabolites by LC-MS/MS-based lipidomic analysis. The treatment with a sEH inhibitor significantly modulated 11 out of 69 eicosanoids, including increased epoxides 12(13)-EpODE, 12(13)-EpOME, 13-oxo-ODE, 15-HEPE, 20-COOH-LTB4 and decreases several diols 15,6-DiHODE, 12,13-DiHOME, 14,15-DiHETrE, 5,6-DiHETrE and 16,17-DiHDPE. Overall the inhibition of sEH in the rheumatoid arthritis model enhanced epoxides generally considered anti-inflammatory or resolutive mediators and decreased several diols with inflammatory features. These findings support the hypothesis that inhibiting the sEH increases systemic EpFA levels, advancing the understanding of the impact of these lipid mediators as therapeutical targets.

Interleukin-19 promotes bone resorption by suppressing osteoprotegerin expression in BMSCs in a lipopolysaccharide-induced bone loss mouse model

Aims

Osteoporosis is characterized by decreased trabecular bone volume, and microarchitectural deterioration in the medullary cavity. Interleukin-19 (IL-19), a member of the IL-10 family, is an anti-inflammatory cytokine produced primarily by macrophages. The aim of our study was to investigate the effect of IL-19 on osteoporosis.

Methods

Blood and femoral bone marrow suspension IL-19 levels were first measured in the lipopolysaccharide (LPS)-induced bone loss model. Small interfering RNA (siRNA) was applied to knock down IL-19 for further validation. Thereafter, osteoclast production was stimulated with IL-19 in combination with mouse macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). The effect of IL-19 was subsequently evaluated using tartrate-resistant acid phosphatase (TRAP) staining and quantitative real-time polymerase chain reaction (RT-qPCR). The effect of IL-19 on osteoprotegerin (OPG) was then assessed using in vitro recombinant IL-19 treatment of primary osteoblasts and MLO-Y4 osteoblast cell line. Finally, transient transfection experiments and chromatin immunoprecipitation (ChIP) experiments were used to examine the exact mechanism of action.

Results

In the LPS-induced bone loss mouse model, the levels of IL-19 in peripheral blood serum and femoral bone marrow suspension were significantly increased. The in vivo results indicated that global IL-19 deletion had no significant effect on RANKL content in the serum and bone marrow, but could increase the content of OPG in serum and femoral bone marrow, suggesting that IL-19 inhibits OPG expression in bone marrow mesenchymal stem cells (BMSCs) and thus increases bone resorption.

Conclusion

IL-19 promotes bone resorption by suppressing OPG expression in BMSCs in a LPS-induced bone loss mouse model, which highlights the potential benefits and side effects of IL-19 for future clinical applications.

Septic arthritis of the hand: From etiopathogenesis to surgical treatment

BACKGROUND

Septic arthritis of the hand, which is the second most common after damage of the knee joint, remains one of the leading causes of temporary disability. An inflammation can cause dysfunction of the joint, and in the most severe cases, the need for amputation of the finger may arise. The results of their treatment today, especially from a functional point of view, cannot be considered satisfactory. Urgent surgical treatment is extremely important in septic arthritis of the hand, as it helps to prevent cartilage destruction and the development of osteomyelitis.

AIM

To explore the features of the course of septic arthritis of the hand as well as approaches to surgical treatment and its results, depending on the nature of the damage to the articular structures.

METHODS

The results of the treatment of 170 patients with septic arthritis of the hand, which were treated in the period of 2020-2021, were analyzed. Inflammation of the interphalangeal and metacarpophalangeal joints (MCP) of fingers 1, 2, and 3 was more often noted in 147 (81.6%) joints. The most common cause of arthritis was a penetrating injury as a result of household trauma (101, 59.4%), animal bite (30, 17.6%), and clenched fist injury (15, 8.8%). Septic arthritis with contiguous osteomyelitis was observed in 98 (54.4%) cases. Surgical treatment was completed with drainage and irrigation of the joint. Early mobilization was used to restore function. In patients with osteomyelitis, it was aimed at the formation of neoarthrosis. Arthrodesis was not applied. Long-term results of treatment were assessed in 142 (83.5%) patients within 1 mo to 12 mo after discharge from the hospital [the median was 7 mo (IQR: 4-9)].

RESULTS

The most commonly isolated organism was Staphylococcus aureus (35.3%). The median treatment delay in patients without osteomyelitis was 5 d (IQR: 4-7); for septic arthritis with contiguous osteomyelitis, it was 14 d (IQR: 5-21). Radiography for osteomyelitis within 2 wk was uninformative: 41.2% of diagnoses. A single surgical treatment was required in 138 (81.2%) patients, two treatments in 22 (12.9%), and three or more in 10 (5.9%). Total elimination of the infection was achieved in 163 (95.9%) patients. The best functional results of treatment were noted in patients without osteomyelitis. After septic arthritis, Total Active Motion (TAM) for the MCP was 96.2% (IQR: 85.1-98.0), for the proximal interphalangeal joint (PIP) 82.4% (IQR: 54.5-98.5), and for the distal interphalangeal joint (DIP) 69.4% (IQR: 65.4-74.1). In cases with osteomyelitis, it was possible to achieve the formation of neoarthrosis with TAM for MCP-64.2% (IQR: 45.3-90.1), for PIP-62.5% (IQR: 41.8-68.9), and for DIP-59.4% (IQR: 50-62.1). Additionally, the severity of pain during movements did not exceed 1 point.

CONCLUSION

The delay in treatment of patients with septic arthritis of the hand was accompanied by a high incidence of osteomyelitis, especially in the presence of diabetes mellitus. Urgent surgical treatment, along with continued irrigation of the joint and antibiotic therapy, made it possible to eliminate the infection, and early rehabilitation restored the range of motion. The best results were noted in patients without osteomyelitis. With the development of osteomyelitis, a complex of early rehabilitation measures also made it possible to partially restore the range of motion due to the formation of neoarthrosis, without resorting to arthrodesis.

Septic arthritis of the hand: Current issues of etiology, pathogenesis, diagnosis, treatment

Septic arthritis of the hand is a serious disease that often results in dysfunction of the joint or even the need to perform amputation of the finger. They rank second in the frequency of occurrence after lesions of the knee joint. Many points concerning the etiology, the timing of the development of cartilage destruction and the development of osteomyelitis, approaches to surgical treatment, the duration of antibiotic therapy, and the start of rehabilitation measures remain the subject of numerous discussions. Based on a search in the PubMed, Web of Science and Google Scholar databases down to 1990-2021, publications on septic arthritis of the hand were found and analyzed. The following inclusion criteria were used in our review: (1) Septic arthritis of the hand; (2) Published in a peer review journal; (3) Written in English; and (4) Full text version available. Studies were excluded if they met any of the following criteria: (1) Letters; (2) Articles published in abstract form only; and (3) Cadaveric studies. Septic arthritis of the hand was characterized by the most frequent damage to the joints of the index and middle fingers (> 50% of cases). Up to 90% of cases, the infection enters the joint as a result of penetrating trauma, animal bites, etc. Staphylococcus aureus became the most frequently isolated microorganism (30%-55%), and its polyantibiotic-resistant form Methicillin-resistant Staphylococcus aureus was found, according to various sources, from 0% to 73% among all isolated Staphylococcus aureus. In arthritis, Pasteurella multocida (6%-11%) is often isolated as a result of animal bites. Articular cartilage destruction in the experiment developed within 24-48 h after infection. In clinical studies, the development of osteomyelitis was noted when treatment was delayed by more than 10 d. X-ray data during the first two weeks were uninformative. Priority of surgical treatment of septic arthritis. Drainage and surgical treatment, and with the development of osteomyelitis, the implementation of arthrodesis. Antibacterial therapy for 2-4 wk and early start of rehabilitation measures. Timely surgical treatment in combination with antibiotic therapy and rehabilitation makes it possible to obtain a positive result in the treatment of septic arthritis of the hand.

Exploring the Role of Staphylococcus aureus in Inflammatory Diseases

Staphylococcus aureus is a very common Gram-positive bacterium, and S. aureus infections play an extremely important role in a variety of diseases. This paper describes the types of virulence factors involved, the inflammatory cells activated, the process of host cell death, and the associated diseases caused by S. aureus. S. aureus can secrete a variety of enterotoxins and other toxins to trigger inflammatory responses and activate inflammatory cells, such as keratinocytes, helper T cells, innate lymphoid cells, macrophages, dendritic cells, mast cells, neutrophils, eosinophils, and basophils. Activated inflammatory cells can express various cytokines and induce an inflammatory response. S. aureus can also induce host cell death through pyroptosis, apoptosis, necroptosis, autophagy, etc. This article discusses S. aureus and MRSA (methicillin-resistant S. aureus) in atopic dermatitis, psoriasis, pulmonary cystic fibrosis, allergic asthma, food poisoning, sarcoidosis, multiple sclerosis, and osteomyelitis. Summarizing the pathogenic mechanism of Staphylococcus aureus provides a basis for the targeted treatment of Staphylococcus aureus infection.

Neutralization of IL-17 and treatment with IL-2 protects septic arthritis by regulating free radical production and antioxidant enzymes in Th17 and Tregs: An immunomodulatory TLR2 versus TNFR response

Septic arthritis is a destructive joint disease caused by Staphylococcus aureus. Synovial inflammation involved Th17 proliferation and down regulation of Treg population, thus resolution of inflammation targeting IL-17 may be important to control arthritis. Endogenous inhibition of IL-17 to regulate arthritic inflammation correlating with Th17/Treg cells TLR2 and TNFRs are not done. The role of SOD, CAT and GRx in relation to ROS production during arthritis along with expression of TLR2, TNFR1/TNFR2 in Th17/Treg cells of mice treated with IL-17A Ab/ IL-2 were studied. Increased ROS, reduced antioxidant enzyme activity was found in Th17 cells of SA infected mice whereas Treg cells of IL-17A Ab/ IL-2 treated group showed opposite effects. Neutralization of IL-17 after arthritis cause decreased TNFR1 and increased TNFR2 expression in Treg cells. Thus, neutralization of IL-17 or IL-2 treatment regulates septic arthritis by enhancing anti-inflammatory properties of Treg via antioxidant balance and modulating TLR2/TNFR response.

Novel therapeutic interventions towards improved management of septic arthritis

Septic arthritis (SA) represents a medical emergency that needs immediate diagnosis and urgent treatment. Despite aggressive treatment and rapid diagnosis of the causative agent, the mortality and lifelong disability, associated with septic arthritis remain high as close to 11%. Moreover, with the rise in drug resistance, the rates of failure of conventional antibiotic therapy have also increased. Among the etiological agents frequently isolated from cases of septic arthritis, Staphylococcus aureus emerges as a dominating pathogen, and to worsen, the rise in methicillin-resistant S. aureus (MRSA) isolates in bone and joint infections is worrisome. MRSA associated cases of septic arthritis exhibit higher mortality, longer hospital stay, and higher treatment failure with poorer clinical outcomes as compared to cases caused by the sensitive strain i.e methicillin-sensitive S. aureus (MSSA).

In addition to this, equal or even greater damage is imposed by the exacerbated immune response mounted by the patient’s body in a futile attempt to eradicate the bacteria. The antibiotic therapy may not be sufficient enough to control the progression of damage to the joint involved thus, adding to higher mortality and disability rates despite the prompt and timely start of treatment. This situation implies that efforts and focus towards studying/understanding new strategies for improved management of sepsis arthritis is prudent and worth exploring.

The review article aims to give a complete insight into the new therapeutic approaches studied by workers lately in this field. To the best of our knowledge studies highlighting the novel therapeutic strategies against septic arthritis are limited in the literature, although articles on pathogenic mechanism and choice of antibiotics for therapy, current treatment algorithms followed have been discussed by workers in the past. The present study presents and discusses the new alternative approaches, their mechanism of action, proof of concept, and work done so far towards their clinical success. This will surely help to enlighten the researchers with comprehensive knowledge of the new interventions that can be used as an adjunct therapy along with conventional treatment protocol for improved success rates.

Etoposide-mediated depletion of peripheral blood monocytes post s.aureus infection attenuates septic arthritis by modulating macrophage-derived factors responsible for inflammatory destruction

S.aureus induced septic arthritis remains a serious medical concern due to its rapidly progressive disease profile. The multidrug resistant nature of S.aureus demands the development of new strategies for the treatment of S.aureus arthritis. Since monocyte/macrophage population has been recognized as an important axis in joint inflammation and destruction, selective depletion of peripheral blood monocytes might influence the outcome and progression of the disease. Therefore, in this study we have put forward the concept of monocyte depletion by using etoposide, a drug that selectively depletes the monocyte/macrophage population. Mice were inoculated with live S.aureus for the development of septic arthritis. Post S.aureus infection, etoposide was subcutaneously injected. The severity of arthritis was found to be significantly low in the etoposide treated mice throughout the course. Arthritis index, histopathological analysis and TRAP staining images confirmed effectiveness of etoposide treatment in regulating inflammation and bone cartilage destruction. Lower levels of inflammatory cytokines, ROS, MMP-2, RANKL, OPN and plasmin reflected less severe arthritic destruction after etoposide treatment in arthritic mice. The bacterial load was not increased after etoposide treatment. Together, the presented data suggested that monocyte depletion by etoposide might represent an alternative therapeutic strategy for the treatment of S.aureus arthritis.

Potential anti-arthritic and anti-inflammatory effects of TNF-α processing inhibitor-1 (TAPI-1): A new approach to the treatment of S. aureus arthritis

Treatment of septic arthritis has become more challenging due to the rise of multidrug resistant strains of Staphylococcus aureus (S. aureus) in recent years. Failure of antibiotic therapies has compelled to initiate the search for new alternatives. This study aimed to unveil the potential anti-arthritic effects of TAPI-1 (TNF-α processing inhibitor-1), an inhibitor that inhibits TACE (TNF-α converting enzyme) mediated release of soluble TNF-α and its receptors along with attenuation of other inflammatory and joint destructive factors responsible for the progression of arthritis. Male Swiss albino mice were inoculated with live S. aureus (5 × 10⁶ cells/mouse) for the development of septic arthritis. TAPI-1 was administered intraperitoneally (10 mg/kg body weight) post S. aureus infection at regular intervals. Throughout the experiment, the severity of arthritis was obtained to be significantly low after TAPI-1 administration. Arthritis index and histopathology confirmed effectiveness of TAPI-1 in mitigating inflammation induced paw swelling and less bone-cartilage destruction in the arthritic knee joints. Lower levels of soluble tumor necrosis factor alpha (sTNF-α) and soluble tumor necrosis factor alpha receptor-1 (sTNFR-1) were detected in the TAPI-1 treated group suggesting TAPI-1 mediated blocking of TACE with subsequent inhibition of TNF-α signalling. Treatment with TAPI-1 lowered the levels of reactive species; matrix metalloproteinase-2 (MMP-2), receptor activator of nuclear factor kappa-B ligand (RANKL) and osteopontin (OPN) denoting less matrix degradation and less osteoclastic bone resorption. Together, this experimental work authenticates TAPI-1 as an alternative therapeutic intervention for the treatment of S. aureus arthritis.

Advanced septic arthritis of the shoulder treated by a two-stage arthroplasty

BACKGROUND

The usual treatment of septic shoulder arthritis consists of arthroscopic or open lavage and debridement. However, in patients with advanced osteoarthritic changes and/or massive rotator cuff tendon tears, infection eradication can be challenging to achieve and the functional outcome is often not satisfying even after successful infection eradication. In such cases a two-stage approach with initial resection of the native infected articular surfaces, implantation of a cement spacer before final treatment with a total shoulder arthroplasty in a second stage is gaining popularity in recent years with the data in literature however being still limited.

AIM

To evaluate the results of a short interval two-stage arthroplasty approach for septic arthritis with concomitant advanced degenerative changes of the shoulder joint.

METHODS

We retrospectively included five consecutive patients over a five-year period and evaluated the therapeutic management and the clinical outcome assessed by disability of the arm, shoulder and hand (DASH) score and subjective shoulder value (SSV). All procedures were performed through a deltopectoral approach and consisted in a debridement and synovectomy, articular surface resection and insertion of a custom made antibiotic enriched cement spacer. Shoulder arthroplasty was performed in a second stage.

RESULTS

Mean age was 61 years (range, 47-70 years). Four patients had previous surgeries ahead of the septic arthritis. All patients had a surgical debridement ahead of the index procedure. Mean follow-up was 13 mo (range, 6-24 mo). Persistent microbiological infection was confirmed in all five cases at the time of the first stage of the procedure. The shoulder arthroplasties were performed 6 to 12 wk after insertion of the antibiotic-loaded spacer. There were two hemi and three reverse shoulder arthroplasties. Infection was successfully eradicated in all patients. The clinical outcome was satisfactory with a mean DASH score and SSV of 18.4 points and 70% respectively.

CONCLUSION

Short interval two-stage approach for septic shoulder arthritis is an effective treatment option. It should nonetheless be reserved for selected patients with advanced disease in which lavage and debridement have failed.

Expression and significance of autophagy genes LC3, Beclin1 and MMP-2 in endometriosis

Expression of autophagy-related proteins, microtubule-associated protein light chain 3 (LC3) and Beclin1, and matrix metalloproteinase-2 (MMP-2) was investigated in serum and peritoneal fluid of patients with endometriosis (EM). The messenger ribonucleic acid (mRNA) expression levels of MMP-2, LC3 and Beclin1 in endometrial tissues of EM patients and correlation of these genes with EM and their significance were evaluated. The serum, peritoneal fluid and endometrial tissues of 84 patients treated in The First Affiliated Hospital of Qiqihar Medical University (Qiqihar, China) from March 2016 to March 2017 were collected. The serum, peritoneal fluid and endometrial tissues of 42 EM patients were used as the experimental group, while those of 42 non-EM patients were used as the control group. The levels of LC3, Beclin1 and MMP-2 in serum and peritoneal fluid of EM patients and non-EM patients were quantitatively detected via enzyme-linked immunosorbent assay (ELISA), followed by comparative analysis based on data in both groups. In addition, mRNA expression of LC3, Beclin1 and MMP-2 in the endometrium in both groups were detected via reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and differences in expression of these genes between the groups were analyzed and evaluated. Correlation of LC3, Beclin1 and MMP-2 with EM was explored. Results of ELISA showed that levels of LC3 and Beclin1 in the EM group were significantly lower than those in the control group, while levels of MMP-2 in serum and peritoneal fluid of the EM group were significantly higher than those in the control group (P<0.05). Results of RT-qPCR revealed that mRNA expression of LC3 and Beclin1 in the endometrium of patients in the EM group were obviously decreased compared with those in the control group, while the expression of MMP-2 was high, and differences in expression were statistically significant (P<0.05). The expression of MMP-2 is high, and expression of LC3 and Beclin1 is low in serum, peritoneal fluid and endometrium of EM patients, and investigating the expression of MMP-2, LC3 and Beclin1 in EM is helpful to further clarify the pathogenesis of EM, and guide the clinical diagnosis and treatment.